One-handed zooming like the Maps app

I would love to have the double-tap-and-hold zoom feature that exists in the Apple Maps and Google Maps apps.
Double-tap, keep your finger held down, now you can change the zoom level by sliding up or down. The new zoom level remains set after lifting your finger.

I’m aware of the two options that already exist for one-handed zooming. (1) double-tap, and (2) hold-and-pan.

Double-tap is a great starting point, but then I often want to make small adjustments.

I haven’t found hold-and-pan to be useful to me. The zoom level can’t be adjusted, and it zooms back out once you lift, which is not what I want.

The double-tap-and-hold option, a la Apple Maps, would be perfect, and could coexist with the other two methods.

Thank you. Panels is very well designed software. Kudos!